This guy I saw last year at a party was dressed as a "one night stand." He wore a cardboard box with drawers drawn on it and a Lampshade on his head. Get it?
Ok anyway... I've seen a lot of cheesy couple costumes online if you want to go that route. Like the Plug and Socket, a Nut and Bolt.... etc.
I decided on being a harem girl. I just need to get a fake tan otherwise I'll glow bright white.